SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a47c55178d973b6393d04ce2b2a02d515010d3ebe067837310844d446fc1128' 
  AND token = 'f0zvlWkn/pIkzBGvXHn6xkcvFFnZKYU66S5ShD2wjHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}