SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ccda131b4c073e784da722550a4e3beb796d0b01b6868330a8efd12812ea23a' 
  AND token = '1wMmGpYN+xkb9oqy4XXMvYQxoj4uG+QlX/DW02rJnVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}