SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebb6c9041bc5184af23c766e4ab0f9ff65639c5e1f82e923c70fcba76ff0ea51' 
  AND token = '7OEXMWwkzqmK+RUYB0ROixKpLpZx/dbWWNYkH/DP4ZI=' 
  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"
    }
  }
}