SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f9cc79122fd6a4c4a393234ab5b018b4246dbc7325a211bdc46c1837f47458f' 
  AND token = 'R/cNtgfe9ukl6dJ59RTXk+u/vkPGmVef43+vAqcbtcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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