SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ca09e777f8b9a02f6be19718135420ddbbc985815de28afd19153853def8e4' 
  AND token = 'uQBM3X8vq48DDeZ3Ly/FkwLMVkxpEsJOEPcgE/77qNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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