SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc18ef8fa77330fd764584cadb1be92bd2c4761507666f5c7c97cd770ef8ca00' 
  AND token = 'HxETUJZlMcTt7R9btahPNI/n51uOPWoaH2bGo+MCTVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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