SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aba1d5e55824c663816670dc990fc9bfcd106a4e31b18834de9d0e91e7928a56' 
  AND token = 'hipK5xs12Fl6CO5IuZfQde/U/XNSqS7BYkoy3ykN87E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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