SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fa32c898576f9d3facb644d782d1fe821694d11b824e88f443764cbff80b822' 
  AND token = 'iSEJ4OL/BB493JQV9RyNNA9UiYgygSm3LXwVAuXA7Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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