SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d317403362b6cc1e16f32aa2ce8337025921a772067244ef07b489a8552adfd' 
  AND token = 'gJR7vpV06jsS4VQw1CZqp8+wCyuNbagk72UzE2rmODU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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