SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f11a8eb099995c28202eb83d3adcba7a61c7ba684f544344ea2fa366a67b8b57' 
  AND token = 'RocUvPjGy7Gp9jIY+Z0pVrYAfxx+Xk/O1tnVEKOZFWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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