SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3f6ee18bbe27fac82e2e75a9c3f8d4fe70479865f7927aa6e358e6214f9aba9a' 
  AND token = 'uUHr7fxiIhxKCM5/7wIu0yLgxfKIriCPWWtrcsHGZz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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