SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3463ffb439915e17c91963f1bb0b40a685dfafc439ce2470700b84fb5959370c' 
  AND token = 'EV1J4M4PdP8Tekpe9SnxxB5RvhckAymyrMd6yiLaW3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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