SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6203f39637887338b731b028605662f74e479d7deca602a9d779aac64b1ebd5d' 
  AND token = 'M48j2MyqzQ29qWvzOHPmOzaAg+vZZTkoP45NePKJqn8=' 
  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"
    }
  }
}