SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39ed9685860bb7fd5cefbef55d5a931155e6a3cf690238795c302a768227727a' 
  AND token = 'IEAqSpCXpS0YBtRTgotPNKerLWo9FYKN1Ala9kPXK/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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