SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '780435da9a55d2616ecc567421e84b2e7475f3ae8c61124c3073d8cbbfd11e4b' 
  AND token = '0l4w7A3zJLhkMj/f1DjY5iG6SYlAxSiEhX9fMg4mcQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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