SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca66bdd9bd4361ec1aa7c08d49b2c6d94919c0d293767308de0b1397dbf2a759' 
  AND token = 'MBf0ChSC/WcUmwwHQDA7WAL72JcdNq3AD5Rrvw8akpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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