SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df512a72bd2c689d2a2d242ed30a17e66f5fbf211be6fd5c6f1323217371fdbd' 
  AND token = 'aBpn49bawOBnjWrOZIWKlBTYK5IUS+IZeEmGZzBHq/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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