SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63fc71446ef90bec8d3380734ad1be7e2a111b908204829501fd0addb4499bf8' 
  AND token = 'DERgPIxe6cMjLID+ae+kIQB8aZ3RUy/ibCqVdppZrbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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