SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b068a408b4ae19918fc1be0c7289ebe89d839d2d99a829dea388bad0c6c634d1' 
  AND token = 'PkH9jjgi7/ooDLqH4TkSCj0O5G2h3BCzkbW4w0Bbah8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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