SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65892e841d39b274c0ff47f6f36fbe66b9398a88316caa078e098495a15d0969' 
  AND token = '3BxW+dSBlZUYDTMBaDBAUhNwl6OuWTGOMCQCKITBwhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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