SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1859aac8de06727c70da8e4ef7b6a21b1f2b4483b54b3c480344f194ea649ac4' 
  AND token = 'Fq7nTTuwTBmUkM+vlSkHPxr5DjoiWgbVSwafp/WNvjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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