SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba3521202e73fed77de823c7703b8602af2a1f697ef589597f8ea7fbec5403ee' 
  AND token = 'l4PJhyzbeETXw6jPQMDmUCT6YHX3tu3zWCJ7OrF8tq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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