SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ce03b3daacb7fdc1eb8cb72b95fc80ed45c7436ea795f5b52fa55827b0630d1' 
  AND token = 'RvZ6GAbvRwvVNTHIfoehlM6tAdRRcR+5AFxW+UJcrJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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