SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05dd50613ae562b78bbc3db10a7e91de52c073b00ff0d54045086a3fb988e719' 
  AND token = '+TVoD4VPwmmid4gw6FKMn2ngOFjZoOpvOqXNOSv3W7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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