SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ca437e4edca55d81eac53f6acbafeadcc7ca42f4cd2e894bc254a58286eaa32' 
  AND token = 'NiEntRJagcPYJPCKZxGidgNbBKsuMxvLaUBbpCbz0J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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