SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c4b5bcee75676ff6a94aec266fb95bfbc732d6dbe7dd92e55b30b8c15482d7f' 
  AND token = 'KdCGcjdZLp+728H1yPO/ubvIgSue9li/ALvXW51yMPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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