SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2347767efd57287971009ad079c1facf390187fe8594aba5ceaf5ec9dba359fe' 
  AND token = '86EGjIPzY3JFU2Pb8q4WkRw6P9ufMtza7G0jaedevDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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