SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7ec4996178b771ed029895bf37b117262ffe00ee0543297054fc1922725498c' 
  AND token = 'gyYKXxS4oWyLjTDsNCGzLaoH0i1FPS1ld7LOuc1bY1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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