SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bda6bdafe3fc2636a0d552d15de51e802ce97c9b9241cdfe391c1495437b164f' 
  AND token = 'AeygX/QYdZxBWgS0jObhQ1CS5keUzA1JUXNaT2doU9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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