SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92212b75a7852ce0316134ea7bd94c1ac734304e198d82123ff7684c5c5081b2' 
  AND token = '9rtWdk8ddaQvLMIzkMgwRMK/7ryOts2csCEgPLxLXfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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