Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3989181141d4e996b9762e0f2a981ec2f4feb0a0384baeb365aae727a390965' 
  AND token = 'yCBewn3R76/cOdZQnHNccLTiifU2f1bQgwRib6topCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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