SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd16fd70f3e6fb5dcdcce69c23b147eee9af4a1ea79e998a684324dba079edf85' 
  AND token = 'qY2VZwC2CvAHV9Vok+EEKu9dKjAtr49kMPEEO9FBOkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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