SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '794a50244a7dbd5a68996595d5009ceef777ee3555c2e8137293af9057ed4717' 
  AND token = 'dk5Y9mzRpIcJFdjSmdGc63HW9NWyTbf1/eYCoRasSxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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