SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3870e84541a6c2fde9396740f11d1dcc27600e70922577b4ed54028f5b55c4d3' 
  AND token = 'KcMv5XuXzapQdF4XnB12t4dRw0PXzSngUy5hNo8TuZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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