SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf576ff236bbe38bd1528be69904ebecdefdde2eebed6b0068bf00e24ec06d02' 
  AND token = 'ZNowRJIT8cGxvn0HmgDMYc+WXoRdICFfdJCqdErSGr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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