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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4e1b8b42bb3269e0c3ba1423d4af88174c5e3e223c2f1ff76e4bc94c442dc18' 
  AND token = 'RN07EM5SKkIuF1zXHgxr3d4iSHSbqYprTyG1MtlU1RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}