SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00db1c99f9a38fd7df7c1c4f57690263423cfaae536cc8db6e9fc208c83abe59' 
  AND token = 'nNXNWBbAdwAxPDwEZe7o9XnKOCorZsOeEnoyOjg1ZFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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