SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0ad266f75965b3b5b9f6260b437b451f98c43163de3434386a919b1da4353dc9' 
  AND token = 'pxT30oqu9/RZIEg7DBBE/0VjK7prupqXRtRIWUD8QqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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