SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15df00fca7913fbf784eb412d1df8082d8bde33b367ca4753060fd0e2599dc59' 
  AND token = '2F/5xEtPCcsUaAwiVfg/lqTQJOSqyJdGY6Mb1BXGUuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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