SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6fa3bfb9dd40c483a96832f1052c6613ff7f4edac3edfd7743f1280069fb737' 
  AND token = '4wq94GaSuPLb34p5Ue41oE7HnkduKYmBP/sGOnJToKk=' 
  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"
    }
  }
}