SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9e2bd32e4b7eceb3b5360c41999e04068e19fedbf767fae19991be55d2fcfed' 
  AND token = 'DOJ3FrruYN3oHcEI6QuYPtrde6wBibFSFWO3k/BLLMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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