SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af9f9be9b018c12d758e2086d39775258e22440ab800c1e67ca8b8455dcd23e6' 
  AND token = 'vnxXb655GVwKNrq2RAL3GF7KT4ioJcBsGXaQ8PQyIlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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