SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07fa351355eac2e01a6dbc7e006689fcdcb42a2d63c9c91b9ed30c4c063b1519' 
  AND token = 'fj5nwv/HeJnXQrfumQ4m98rjDckEOwG9kmnXV1OMEug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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