SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fad581ed4f727c931e88580c4bbdd6623771ffc81e02337cd356951a25fb3f25' 
  AND token = 's46dM8EPkgw1mupXL6Av/89eCJraefeiyboCwSyc8XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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