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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f90b1e6ed8defaf22d35d6210f81f3e4e2b47319f16fdcb4a176583a1c00dca0' 
  AND token = 'p3V1h93KXTLQ1gkdPjJQEtBMAqinVV1PZ+KAtCWYo1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}