SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2cfe5fb34722ddb406b3284d0692dc23f857c954d2c589ddadbb83dc7adad90c' 
  AND token = '7gYD0e7CNVvBVX0zuez/tPwfk+iAkG4X16QDA7H4iTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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