SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e31b0638f37c98a073c94649fb4ebff6747934ab22eaca791fdb299ba5a527f2' 
  AND token = '2OoeaJBtTmjp5SFkDjit01FSkrDzm51OZTCv0TPKHlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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