SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd737304b06aadc6d814b2a2795250a54603ae44d52661cb7f685610ff21d5826' 
  AND token = 'z0VrPwB1rJX7QBXw93hlYj1+jh3AQnt6H5kh5mtkzZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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