SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56fff1221d642d021fe2f9194fb102d33678c8715396ca8525e374ffe605f57' 
  AND token = 'Uhnk9Pw4xblbWAhDKn82Mbg/mYpyxd+i+71SrBZn6ws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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