SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1afa08abcc34b663d65af139d23840142bf6620b3c8d208d85e3563c7c637b' 
  AND token = 'CF2BtSuTBYwoiBJSZGfTiWPu9kPeXopLjwAfuqW3b+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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