SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e2c83fc6543fb2a7cd05fd35e3e193c445f68da7ee6db91a370a3d04f80fbacc' 
  AND token = 'FJQn8ZyHUwOMtvg1Enq0KW/Y/OaN4m8fKu9ywZwaBiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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