SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9e680fa7b0064e5d436a5be3fb8e197fa5e14e9232c9f2b20f044d8df9978fa' 
  AND token = 'mXaRAz3Th1Y1U/0662+xWfgIhAtjhyHWGvjjcH5zF/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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