SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8487f914536b9d2b1e9a83b5ddd44f2d7fce53fc865ab425362e8b89c235c88f' 
  AND token = '2L2lJhBowSSQwbMShzaFgUIZKHidLWgA10r7NRbgj34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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