SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14705637d138a6c97a0e664c42bfcda33f06536448170ea834c733af94d63f0b' 
  AND token = 'wmWd/wUrQ7774yyv9OGRKHXmQVmn0k0thqEGnJPOQVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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