SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48b489ad3c9cc5220669a7a084f11b57a4baae8dae32575fc1711399cde45778' 
  AND token = '2Vqw2u3bjhBn1AorIV2mWNaBCI+JMYtMxE6zRw+xErM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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