SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecddbfece994a9a58386bf4df10c8f195a87be2d5d8f4208ab2e49d0ed8d0bc0' 
  AND token = 'ScA05X3tKh8VTzeVsB9wuRdq2QVHtmizttK7lFyrwA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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