SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91dc3435cefd823b519de663d0934b5ba634bf7ba918455aeca615bdef024a00' 
  AND token = 'xQjEVh4lfjBVOj97VUlNp+s6BhbRRiJNqmg/lI6ZRiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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