SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6bfed9284eac701b7219c130fbb0ee91ad92d4bb082c3d3db15b1d8478db5df' 
  AND token = 'euNOG2+MPz5yWzNqgN8teVTwsqFeeIqB3/0a9dpgVIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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