SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d615b042bac67fcde6dc05bb4f3cc6ed4a565244be4bf0fcf955ffce5478c80' 
  AND token = 'YY9FTrJF8iyxlaf1Hxqj0BVe9ESsL1ZDq3CpV09xBJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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