SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deeadc909fd3d751e7ec02d59636d42187b90e5b4eca8cc4c48932b479fb7543' 
  AND token = 'Y7/cvsaSsQpDqzGQzzgm0Wrr0wlPZFgtg6eLnDnJ+p4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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