SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a11fa2f954b40d39c599770adee8eca803a3b8297d4e40b64d37d4afb74f67d3' 
  AND token = 'BFFrIhijWNG/9UD+jVdWIBQZrR81PEnrMFIXZ6FcKJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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