SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '144525d8289ff0112feb0634042dc67e7ffc56d3ee07541190eb7372190209c7' 
  AND token = 'oFZaoake1OWamwTK2uznsQjGsCcTQFeWDwos4oCZNLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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