SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcadc19a4ff3120fe637e5637196590253b583f5aa42db7b18b558325a4293c2' 
  AND token = 'lYXOwf33YP8MgFun8uW3kTskLJpQK7iYKuqshKe9css=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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