SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1c462685ed751cc839ff81ee3caeff38bf50054f3df4913899b0ee71f4164e3' 
  AND token = 'ENRu89EOlBgz/A+jaJg/FDfO6YxFcrONtYY0NuCivGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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