SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a47adf344092b4f862c9def85e1823fa25f1d9535c90e9f267619ab3b5c22146' 
  AND token = 'KvI0QT6saTfTu8Byb7HJvoVcPQwcXZyFd8zI6+3IyVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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