SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a229f51cb6ab4f245a80c920ec1b0daba4b72e6cfc9bb086d0403315d9ef79e' 
  AND token = 'tDVvodsVb4lJFVVzEPrQK4xL/LDTV7bYHL5zauj9Bj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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