SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948c389881a9c5597a4ab880d06444fafc66792a439962759bb7458a333dbcf3' 
  AND token = 'lyONNUawnCHyQedW0r4iOAdCgSjSvb7SaVNjesJTCWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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