SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffea2dd2f43a425ea079ffd4b33c7ddb636f4298abe19dcb1a01381e2fd4c017' 
  AND token = 'OHqyCu1LbmPGe7Sdx1j65tjP2X7FvIj3O7le/4eywyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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