SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e9069aabaf4b547cb44dd4225658d1c4b75c8187033e909f739f3ad4b7667e2' 
  AND token = 'u5M9uiIGnedkYkhSLYKJ1JUpqYNZ0a66wIxMPjqhf7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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