SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f64a16afe5b5e24572c0effcaab26de3cf79ce7071cd0189549f6a72c1fd59b8' 
  AND token = 'SkyZ3pWUjTtnaClbmILrmut/BzLEudVM1MqVbJdSMkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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