SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e6f9a93a3bd6f20edf9784614b0afe3bdbeb53376f4b619dad0bc046de12f62' 
  AND token = 't5/+4xk+jEGULrhqvidJ0ZWXMHxRUklv1m9kOso0h30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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