SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f8bd954ffef8255a7decce68eee239b014c9745625b63b6887cb1fd4153cb78' 
  AND token = 'K+DSqLFsyNghVdieL5MfryiEa3KILsc7eD6MLWfzBk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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