SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2f1b09487e961ffebb1e5c425570d6262956003c7fdf631d73e07eca3dc0b2b' 
  AND token = 'fSwoaJfGiqZNJm1xOlFoUYECSVigPA5dVqk6PTzhauU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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