SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e3f09ba01626bd775c2e4843062b83077c2bcccae27b75660a68e56e8efd75' 
  AND token = 'X/a+HEEq+fSQW5XqTSZhKP55Tee1y6pcHXl+wDj4ORI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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