SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c42628db331b15e2589be543951ef1c98e361a61511210d58282cb266303f866' 
  AND token = 'lYpM5/q5FYj6W7PJLSOSVhvX5sBo8S7MY049LTag8Wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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