SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17031b31a21d64b437156d2b208887bb00d38cf7e414493b085fd94019272f37' 
  AND token = 'KNdgMoKem9w86XE+WXFc7Ifm9hKq6Ul7vIj+WJPQaQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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