SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6710266b9144e038fcfb6b28aa5ffd77a030ef11a1fb484cbbdc5d5dbe545e81' 
  AND token = 'Jsmq27KiZIy8nTcc5w2/qdBCAdEfbEvVqTzGs7Xl6AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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