SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e8a971bb9f669b4d4f925307b30cfb8582287d6d7db403166594d4fd7e47da8' 
  AND token = '5ABDQbOmyfhlMsuj2FBxUdXSKHv61yIlKuKmOkBlsMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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