SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '202087ed0f9cea4e0bf1e7020fd1179ed307971ee6889bdd66f404ad1ad790b3' 
  AND token = 'LuNR1CTrhwOlOmRgHdYyF6OZkhFz7iVSpa7A4bZx06A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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