SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491c1df57a64b593e8b52aba82ab5472eab81418b3f574ededbcea7c48f1468f' 
  AND token = '6xjq/kiin07pJVwAuwLkW6+r/ZLR//zGNTvTdLL+2yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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