SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cc4bde0dc6c6911565ceb6c8b5f7275e71f1eb1bda44813ac827eb90c6619d9' 
  AND token = 'f2XJtpn8X20mEPWQzCUAGCKo2UZv2TMOvpA9vpgoV7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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