SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9bf519aa6b752fe5c50ac6672955c67ea51a5dfd3fd1bdc512d28c0ad0b7d75' 
  AND token = 'FNFB0EKwSf9BDpT7nNm5HTAOORazvjDIyH2h+pB/F04=' 
  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"
    }
  }
}