SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24666b320e74fc99bccd06be71e8521df3ce8e0d11d8cce1041ad6eafeaacf46' 
  AND token = 'oGHg+BK7Y5rdiDsgryfbMQDddj6mfezdVgplNvIJliA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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