SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '28a3fbe3a320c8567fd22b187f03acf06ba3f92f3d2fed665d3854cac357b518' 
  AND token = 'U/2RuIlH4+EIxnSvcZO7YrVHyJ8iBnk1P+KCzPJP6ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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