SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7084f6ee98f312203a75199579f8c5c2625b584caa31b6f3cf4974ea5250a92f' 
  AND token = 'QPIRjw59r/fWaQo8EF/ZVJ3/HCSBeS992KQaQi57aak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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