SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd673b90bcf9de6aeef06894b65fd4e6fd3fa2633eef97dad914607bf40341c76' 
  AND token = 'sPYuKbkl9PlRiBv1Yxt1olWJkOsQW0RUJ6uJlgAciHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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