SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04ae45d1b8c622fc42ffef39f59628d7758ca43fde34420a406034ff26bdbc0' 
  AND token = 'qcMCYD3ANr90ihoyeyxyJePrI48QqCL4DYErCQ8vpt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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