SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afbf6d60c21f8f073bc82f42aa57e783a66c6f64fe3d10708b8ffbb6a351d50c' 
  AND token = 'izbi87MeFffE1OihyWrIsn4Gp7Ex+HN6nbR3xpGrxlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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