SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4671daf660abbdd7d0500cd88d913fccc2c985c3aad663ba93dc35e5b359e35b' 
  AND token = 'nJ4N5tYxFIvGhoOv0TjZUAgFdw4nR5wuvH/UiVQeuhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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