SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6bcc63931aee6895c3ac14ebe8adcf72e638baff2e6abcc1876666025a5698' 
  AND token = 'YPU8zeKttZn7ISIIv7c4qagnWbG6z7RUSx2d0aP10iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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