SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '85bb973db7fad13bbd56b1af7b97448012f6bf782aedb57275019146eb3bd8d2' 
  AND token = 'raCYBelNemrVpgFKp+nn4BWp7t+zLNKFmJQgMpnYsPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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