SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7214bfff2aa431986c223ddbfe469f4a78cf5f417b44a2e0fa1c215c78053008' 
  AND token = '9/fg4YRG2ukJ3CtN5SoH4YRYxl1tVX72TvqDBwhUGO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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