SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df2f6b8941136c50a509500c8286c49ffd1c27a4738dd9ea8b77ce1e296d7d4' 
  AND token = '3sY4SZiDdV5/sRNOrDclWwv5QUBSOVJf/hupPPvopnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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