SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5ef6afdef333bbd39df417354418124a7eac43ffb96b1dab0563588d83c0451' 
  AND token = 'fmjnl5ZmPrkA6kBNnGL1cnrFYKQMwp/+B2eYOFhJzKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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