SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfc8a39a1801dac80c2cace18f027f28c9cfaa2bf8740b49ab60993c35f256fa' 
  AND token = '3KOSeIyufasSXUBkn3swOpesLaRmyeJdJASd+vvwZt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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