SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '17f50e84b2532b7b1d562b107fdb3adfee8f14582ba9e882c61905c58955a9f6' 
  AND token = 'LBXJf0mztaZnc5PWNa0OKpqyrrpHzJIJe3vkB3/pVU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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