SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caed591fb5b61fb801ee952795f14e79ad4dbe0eaa5e687c43818cd8bc31c0ec' 
  AND token = 'firaTnkgyZ1wYQL0Km337bj/G27kahCI+m4mYQ3OR0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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