SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31c124c123d8f9f5d428148a4972dbf9f6ef149292c74a03a536b0f69036a317' 
  AND token = 'vqNN8XyhBdCxU0AkeXCzhlKq4+DgwqG4OI1DgHtVZQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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