SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df2f254a5556e13b7d88cfb1835228ab25435f3f5908fe5151aa6c53c22a24fb' 
  AND token = '9it3HooLPYdPTt9pjk7nYHT4jWehp/RaEKO+aRxsXrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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