SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89172268cf69544c2242638835564fd8861016b1de9a63897422cd443ca8c2b2' 
  AND token = 'A2X/xB6wr0IQZiWbZIF0O0vB0cKUWzRbrKJsBswdQmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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