SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '044074a6356747712d948da1d6738b929e81fb39b40f3aed46e0489b28e35ac7' 
  AND token = 'bHaED/cqBXhV5PiJM7xtjeLFGE7zM7jugpJpkEgeA+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}