SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99cfcb73bfa84fd3e96ca534652c86da5bcc2d9afc703fd190c96ec506593f26' 
  AND token = 'M6HzVUdSeflbTxfT3Q5sbwiVlWJV+BPl8yIEFKXGy1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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